A party who has responded to a request for discovery with a response
that was complete when made is under no duty to supplement his response
to include information thereafter acquired, except as follows:
(a) A party is under a duty to supplement timely his response with
respect to any question directly addressed to:
(1) The identity and location of persons having knowledge of
discoverable matters; and
(2) The identity of each person expected to be called as an expert
witness at the hearing, the subject matter on which he or she is
expected to testify and the substance of his or her testimony.
(b) A party is under a duty to amend timely a prior response if he
or she later obtains information upon the basis of which:
(1) He or she knows the response was incorrect when made; or
(2) He or she knows that the response though correct when made is no
longer true and the circumstances are such that a failure to amend the
response is in substance a knowing concealment.
(c) A duty to supplement responses may be imposed by order of the
administrative law judge or agreement of the parties.
